[BUILD] Fix GCC warnning "no previous prototype".
[BUILD] Fix GCC warnning "no previous prototype".

- Set NetworkHeaders_InternalAckPacketDump() as static.

Change-Id: I69f2f0bb9eccd341124fd5b7d73388f6c06bb40c
Reviewed-on: https://gerrit.parrot.biz/29916
Reviewed-by: Jean-Baptiste Dubois <3904e157e51b6776698fd1c0b3e878d58932a523@parrot.com>

Parrot-Developers/libARStream,Parrot-Developers/libARStream,Parrot-Developers/libARStream